Twisting machines, spun yarn winding machines and the like include a cheese package for winding thereon a yarn supplied continuously at a constant speed. During such winding operation, the package is driven to rotate in pressed contact with a friction roller which rotates at a high speed, and the yarn is traversed laterally by a reciprocating traverse guide interlocked by a traverse drum in a cam box through an axis.
The traverse guide is usually subjected to a motion known as "creeping" to prevent uneven winding, that is, package edge rises while the yarn is being wound on the package.
More specifically, the traverse guide traverses the package through a width reduced by a few mm at repeated intervals at each end of the traverse width, thereby preventing yarn rises at the package edges. However, the above creeping motion has failed to completely eliminate the package edge yarn rises.
As shown in FIG. 1, the effectiveness of creeping with which to prevent yarn rises is known as being dependent on the ratio of the time T in which the traverse guide moves with the maximum traverse width to the time in which the traverse guide moves with a smaller traverse width, that is, a creeping time t.
It is known that as the creeping ratio (a=t/(T+t).times.100) approaches 100%, less yarn rises at package edges are produced and the height of the yarn rises becomes smaller.
Increasing the creeping ratio .alpha. in an effort to prevent the yarn rises, however, results in a tendency to give rise to a decrease in the amount of yarn wound at an end of the package, which is known as a yarn shortage, especially when a yarn starts to be wound on a package under high tension.
Further conventional creeping motion is shown in FIG. 10 in which a path T.sub.1 is followed by points reached by the traverse guide at an edge of a package in its traversing strokes. This prior creeping motion however results in two yarn rises at the package edge as shown in FIG. 11, one yarn rise being at an end of the maximum traverse width and the other at an end of the minimum traverse width. FIG. 12 shows another creeping motion which has been proposed to remove the foregoing two yarn rises. The repetitive creeping motion of FIG. 12 follows a path T.sub.2, but still produces a yarn rise as shown in FIG. 13 which is inherent in such a creeping path.